Improvement in adjustable tool-rests for lathes



frvrrED .STATES PATET Y' JOSHUA S.V WHEELER, ASA WHEELER, AND. ORANGEWHEELER, OF WOR- OESTER, MASSACHUSETTS.

IMPROVEMENT IN ADJUSTABLE TOOL-RESTS FOR LATHES.

Specification forming part of Letters Patent No. 116,517, dated June 27,1871.

To all whom 'it may concern:

Beit known that we, J osHUA S. WHEELER, AsnL N. WHEELER, and ORANGEWHEELER, all of the city and county of Worcester and Commonwealth ofMassachusetts, have invented certain new and useful Improvements inAdjustable Tool-Rests for Engine-Lathes; and we do hereby declare thefollowing to be a full, clear, and exact description of the same,reference being had to the accompanying drawing which forms apart ofthis specication, and in which- Figure lrepresents a side view of ourimproved tool-rest. Fig. 2 represents a longitudinal central section,and Fig. 3 represents a transverse central section.

To enable those skilled in the art to which our invention belongs tomake and use the same, we will proceed to describe it more in detail.

The nature of our invention consists in certain improvements inadjustable tool-rests, as hereinafter described.

In the drawing, the parts marked A represent the carriage, which issupported upon the bed of the lathe, and' is arranged and operated inthe ordinary manner. B indicates the base of the puppet-block, and isarranged to slide back and forth upon the carriage A, to which it isattached byfmeans of a dovetailed projection, b, that lits into alongitudinal groove of corresponding shape formed in the upper part ofthe carriage A. The top of the base-piece B is formed arching, and isprovided with a dovetailed projection, D, of corresponding curvature atits central part throughout its entire length, as shown. G indicates thepuppet-block, which is fitted upon the upper arched portion of thebase-piece B, andretained by the dovetailed projection D in such amanner that it can be moved backward and forward over the arched surfaceto raise and depress the point of the cutting-tool and adjust it to theproper height and position. A strip of packing, E, is arranged betweenthe side of the dovetailed projection D and the block C, which strip canbe clamped up against the side of the projection D by means of screws d,set in the side of the block C, as shown in Figs. 1 and 3. Thepuppet-block O is grooved out at its under side, and in its interior isfitted a rack, F, which meshes with a segment-gear, G, secured rigidlyto the upper part of the base-piece B, as illustrated. I indicates anadjusting-screw, which is arranged lonis provided with` a suitablehand-wheel, J, or crank upon its outer end, by means of which it can beconveniently operated. The screw-spindle I has its bearing in and issupported by the end plate K of the block C, and it is held from anylongitudinal movement independent of the puppet-block C by a collar, L,at the inner side of the plate, and the hub of the handwheel J at theoutside of the plate. As the screw 'I is turned the relative position ofthe rack F within the' block changes, but the teeth of the rack, beinginterlocked with the teeth of the stationary segment G, prevent the rackfrom moving longitudinally, and the result is that the block C receivesthe motion and is carried along the curved surface of the base-piece B,thereby elevating or depressing the point of the cutting-tool, accordingto the direction in which the screw I is revolved. When the puppet-blockC is swung over to the front or rear, the rack F rolls down upon thesegment G, so that the same number of teeth will be in mesh between thetwo at whatever position the block may be adjusted. The block isprovided with a lateral groove at its top to receive the puppet andtool, which parts may be constructed and arranged in the ordinary.manner, and consequently require no description. It will be observedthat when the point of the tool is elevated the puppet-block is drawnbackward, and when the point of the tool is depressed said block ismoved forward over the arch of the base-piece B, therebyr changing theinclination at which the tool stands, and thus always prel serving theproper relative position oranglebetween the cutting-point of the toolaud the surface of the work, whether the latter is of large or smallradius or curvature. By arranging the concave puppet-block upon the topof the convex base piece, all dust, dirt, chips and other cloggingmatter falling upon the puppet-block will not be liable. to work in andclog the operative parts of the tool-rest, sincethe tendency of suchclogging substances is to slide off or drop from the puppet-block, thelatter serving as a roof to shelter and protect the internal mechanism.vIt will also be seen that our adjustable tool-rest is simple in itsconstruction and arrangement, and not liable to become deranged or getout of order. Allof the internal parts are closely, incased by the outershell, so as to preclude the gitudinally through the rackF and block C,and

entrance -of chips and dirt to the interior. rest supports the toolrigidly and firmly in any Y ofritspositions, and can be securely held atsuch adjustment by lturning,` in the packing-screws d, and therebyclamping the packing-strip against the side ofthe projection-D. Thesegmentgear G may be made in a separate piece from the base B, and setin and secured by screws, as shown in the drawing; or the base may becast full and the gear-teeth cut directly upon its upper surface. YHaving described our improvements in adjustable tool-rests forengine-lathes, what we claim therein as new and of our invention., anddesire to secure by Letters Patent, is-

1. The combination, withithe base-piece B, provided with a stationarysegment-gear, Gr, of

The-

Witnesses:l THos. H. DODGE,

Urns. H. BURLEIGH.

